Habitat :Yucca brevifolia is native to southwestern North America in the states of California, Arizona, Utah and Nevada, where it is confined mostly to the Mojave Desert between 400 and 1,800 meters (1,300 and 5,900 ft) elevation.Grows on arid mesas and mountain slopes. It thrives in the open grasslands of Queen Valley and Lost Horse Valley in Joshua Tree National Park. A dense Joshua tree forest also exists in Mojave National Preserve, in the area of Cima Dome.

Description:
Yucca brevifolia trees are fast growers for the desert; new seedlings may grow at an average rate of 7.6 cm (3.0 in) per year in their first ten years, then only grow about 3.8 cm (1.5 in) per year thereafter. The trunk of a Yucca brevifolia tree is made of thousands of small fibers and lacks annual growth rings, making it difficult to determine the tree’s age. This tree has a top-heavy branch system, but also has what has been described as a “deep and extensive” root system, with roots possibly reaching up to 11 m (36 ft) away. If it survives the rigors of the desert it can live for hundreds of years with some specimens surviving up to a thousand years. The tallest trees reach about 15 m (49 ft). New plants can grow from seed, but in some populations, new stems grow from underground rhizomes that spread out around the Joshua tree.

The evergreen leaves are dark green, linear, bayonet-shaped, 15–35 cm long and 7–15 mm broad at the base, tapering to a sharp point; they are borne in a dense spiral arrangement at the apex of the stems. The leaf margins are white and serrate.

The flowers are produced in spring from February to late April, in panicles 30–55 cm tall and 30–38 cm broad, the individual flowers erect, 4–7 cm tall, with six creamy white to green tepals. The tepals are lanceolate and are fused to the middle. The fused pistils are 3 cm tall and the stigma cavity is surrounded by lobes. The semi-fleshy fruit that is produced is green-brown, elliptical, and contains many flat seeds. Yucca brevifolia trees usually do not branch until after they bloom (though branching may also occur if the growing tip is destroyed by the yucca-boring weevil), and they do not bloom every year. Like most desert plants, their blooming is dependent on rainfall at the proper time. They also need a winter freeze before they will bloom.

FruitOnce they bloom, the trees are pollinated by the yucca moth, which spreads pollen while laying her eggs inside the flower. The moth larvae feed on the seeds of the tree, but enough seeds are left behind to produce more trees. The Yucca brevifolia tree is also able to actively abort ovaries in which too many eggs have been laid.

Cultivation:
Thrives in any soil but prefers a sandy loam and full exposure to the south. Plants are hardier when they are grown on poor sandy soils. Prefers a hot dry position, disliking heavy rain. Established plants are very drought resistant. The flowers of this species are malodorous. In the plants native environment, its flowers can only be pollinated by a certain species of moth. This moth cannot live in Britain and, if fruit and seed is required, hand pollination is necessary. This can be quite easily and successfully done using something like a small paint brush. Individual crowns are monocarpic, dying after flowering. However, the crown will usually produce a number of sideshoots before it dies and these will grow on to flower in later years. Plants in this genus are notably resistant to honey fungus. Members of this genus seem to be immune to the predations of rabbits

Propagation : Seed – sow spring in a greenhouse. Pre-soaking the seed for 24 hours in warm water may reduce the germination time. It usually germinates within 1 – 12 months if kept at a temperature of 20°c. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in the greenhouse or cold frame for at least their first two winters. Plant them out into their permanent positions in early summer and consider giving them some winter protection for at least their first winter outdoors – a simple pane of glass is usually sufficient. Seed is not produced in Britain unless the flowers are hand pollinated. Root cuttings in late winter or early spring. Lift in April/May and remove small buds from base of stem and rhizomes. Dip in dry wood ashes to stop any bleeding and plant in a sandy soil in pots in a greenhouse until established. Division of suckers in late spring. Larger divisions can be planted out direct into their permanent positions. We have found that it is best to pot up smaller divisions and grow them on in light shade in a greenhouse or cold frame until they are growing away well. Plant them out in the following spring.

Flowers – cooked. The flower buds, before opening, can be parboiled in salt water to remove the bitterness, drained and then cooked again and served like cauliflower[183]. The opened flowers are rich in sugar and can be roasted and eaten as candy. Fruit – cooked. The fruits can be roasted then formed into cakes and dried for later use. Root – raw, boiled or roasted. Seed. Gathered and eaten by the local Indians. No further details are given, but it is probably ground into a powder and mixed with cornmeal or other flours and used for making bread, cakes etc. Immature seedpod. No more details given.

Medicinal Uses:
A good strong infusion of the roots was once a popular treatment for venereal diseases.

A fibre obtained from the leaves is used for making ropes, baskets, sandals, clothing and mats. The whole leaf can be woven into mats etc and it can also be used as a paint brush. The dark red core of the roots has been used as a pattern material in coiled baskets. The core is split into strands, soaked and worked in with the coiling so that the colour is always on the outside. Red and black dyes have been obtained from the roots. The roots are rich in saponins and can be used as a soap substitute. It makes a good hair wash. Wood – light, soft, spongy, difficult to work. Sometimes cut into thin layers and used as wrapping material, or manufactured into boxes and other small articles.

Known Hazards: The roots contain saponins. Whilst saponins are quite toxic to people, they are poorly absorbed by the body and so tend to pass straight through. They are also destroyed by prolonged heat, such as slow baking in an oven. Saponins are found in many common foods such as beans. Saponins are much more toxic to some creatures, such as fish, and hunting tribes have traditionally put large quantities of them in streams, lakes etc in order to stupefy or kill the fish

Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplements, it is always advisable to consult with your own health care provider